function [ X, Y ] = getTrnDataMatrix( this, ds, iRep, jFld, kSubFld )
%GETTRNDATAMATRIX Address training data matrix subsets ...
%                 of i-th rep, j-th fold, k-th sub-fold
% 
% Description
% 
% DataPartition::GetTrnData( this:DataPartition, 
%                            ds:DataSet, 
%                            iRep:int, 
%                            jFld:int, 
%                            kSubFold:int )
%              >>          [ X:DataMatrix, 
%                            Y:DataMatrix ]
% 
% Input
% 
% Output
% 
% Syntax
% 
% Example

if nargin == 1 || nargin == 2 || nargin == 3 || nargin == 4
    error('BatErr: Invalid input arguments.');
end

zId = this.getZTrnId(iRep, jFld, kSubFld);

X = ds.dmX{zId, :};
Y = ds.dmY{zId, :};

end
